Michael is a delightful restaurant owner – he is the epitome of what you might imagine – jolly, jovial, larger than life. And you might be forgiven for assuming that the larger than life part is due to the abundance of food in his restaurants…. Think again. Because every night, on his way home from the restaurant, he buys a 1kg bar of Dairy Milk, and consumes the lot.

Perhaps you’ve done it? You’ve just filled up with petrol, and somehow a bar of chocolate is in your lap, bought in a rush, an impulse at the checkout. You fumble at it, fingers slipping on the wrapper as you try to keep your hands on the steering wheel, heart pounding. You glance at the other drivers. They aren’t looking at you, their focus is on the road. Unlike yours. Your focus is on the wrapper that isn’t tearing.

You put both hands in your lap and rip, and the paper tears. Saliva rushes into your mouth like a dam breaking. The chocolate is already melting with the heat of your lap and the urgency of your desire. You break a piece off, the brown staining your fingertips as you cram it into your mouth. The traffic ahead stops sharply and you slam your foot down, pulse racing as you swallow down the sticky sweetness.

A long drive, you might think? Maybe a two hour commute where he’s hungry and needs sustenance? That’s not the case – his drive is approximately ten minutes. Maybe fifteen if the traffic is bad (which, by the time he leaves the restaurant, it never is). And in that time, during that brief drive, he ate (although I’m not sure this is the best word – perhaps inhaled?) a kilogram of chocolate.

Did he really taste it? Did he enjoy it? Did he focus on it? Or did he shove it down as fast as he could so that no-one would know?

When Michael came to see me, he told me this, with a bit of a giggle: laughter to cover his shame. He knew what the problem was, he just couldn’t stop it.

Snacks are so easy to forget. They are usually high calories and not very filling. In fact some (like a handful of sugary lollies or muesli bars) can even make you feel hungrier shortly afterwards. If we’re eating at our desk, it’s even easier not to register what we’re consuming. Our minds are focused on the spreadsheet, conference call or project, while we funnel foods into our mouths.

If you want a snack, try and get a plate, and make a proper small meal.

I can feel you resisting. “But then I’ll get fat if I eat all that.” “But I don’t want a proper meal’. If you don’t want a proper meal, perhaps you’re not hungry and you actually don’t need a snack either. In the event that you are hungry, maybe it would be better that you register that you’ve eaten something, something substantial, which might sustain you and prevent you from nibbling again in half an hour.

There are other hazards of snacking. The constant stimulation of our stomach means that it never has a chance to rest, or more importantly ‘clean up’. We have brilliant little helpers in our guts that maintain our bodies. If we have eaten a steak, it might take five hours for it to be digested in the stomach and small intestine. Once this is done, the small intestine sweeps itself in a such a cute manner that even tough-minded scientists have called it the ‘housekeeper’. If we eat before it has a chance to do this, it once again goes on standby to receive food. But constant snacking means there is no time for ‘cleaning’ which helps keep our gut healthy.

The drip feed of food also keeps insulin churning up and down. Our bodies don’t have an opportunity to find their point of homeostasis where blood sugar and hormones are regulated, balanced and consistent and don’t have to deal with a constant influx of food. This constant demand for insulin, to deal with the food, can artificially inflate our appetite. So constant nibbling and snacking not only adds to our waistline because we’re not paying attention to it, but also because it makes us want to eat more.

If that isn’t bad enough, if we eat at our desks, we associate being at our desk with eating, which triggers us to want to eat, whether we’re hungry or not. All in all, we’re not helping ourselves.

Step away from the desk. Can you get in the habit of eating somewhere else?

Pavlov is well known for his experiments regarding dogs. When he fed them, he rang a little bell. Eventually, he only needed to ring the bell and the dogs salivated, even when there was no food.

I know we’d like to think that we’re superior to dogs. But there are lots of things in our lives that act like this trigger. Events that induce salivation due to habit. It might be turning on the television, if you usually eat in front of it. Or driving past a garage if you buy snacks when you fill up. Or walking past a certain bakery if you often buy cakes there.

You weren’t thinking of eating a cinnamon roll, were you, until you walked past the bakery and that delicious sweet, spicy smell engulfed you? All at once, your tongue tingles with the anticipation of the sugary coating, the warm, yeasty bread beneath. You find yourself in the shop. A moment earlier you weren’t even hungry.

Or maybe you’re watching television and there is Nigella, dipping her finger into an oozing mass of chocolatey sauce. All at once, the idea of chocolate, or Nutella or a hot pudding fills your mind. The next thing you know, you’re on the hunt for it.

What in your life, acts like that bell, and has you salivating for food whether you’re hungry or not? Can you retrain the dog?

An American professor of nutrition has, in the name of research, spent ten weeks losing weight on junk food. He wanted to prove that it could be done. And it has been done! He has spent weeks on a diet of biscuits, cakes and other high-sugar, fat-laden junk food and has generated a great deal of media hype with tales of weight loss, deeper sleep and better general health.

Mark Haub is an associate professor from the department of human nutrition at Kansas State University. Over ten weeks, Mark ate sponge cakes, biscuits, some raw vegetables and drank full fat milk and a protein shake every day. He lost 12.1 kilograms from his original 91.3-kilogram body weight.

The but (and it’s a big one) is that he carefully controlled his calories intake. He limited his intake to a maximum of 1800 calories (7531 kilojoules) a day, exercised heavily throughout the period and took vitamin supplements in addition to “muscle” protein shakes.

At one point he estimated that he had worked off, and not replaced, more than 800 calories through an abnormally strenuous workout.

“I am not recommending or promoting this approach. I am simply in the process of illustrating that foods deemed to wreck diets, cause obesity, lead to diabetes, etc… do not – in and of themselves – do that,” he said after four days and a 3.2-kilogram loss.

On September 10, he ate:

–a double espresso

–two servings of Hostess Twinkies Golden Sponge Cake

–one Centrum Advance Formula “From A To Zinc” pill

–one serving of Little Debbie Star Crunch cookies

–a Diet Mr Dew drink

–half a serving of Doritos Cool Ranch corn chips

–two servings of Kellogg’s Corn Pops cereal

–a serving of whole milk

–half a serving of raw baby carrots

– one and a half servings of Duncan Hines Family Style ChewyFudge brownie

Until recently, research focused on physical hunger, and assumed that being obese meant you were just incredibly hungry and therefore had to eat loads. I suspect a number of us could have told them that eating dessert has nothing to do with feeling hungry or full. And at last, research is catching up.

Michael Lowe, a clinical psychologist at Drexel University coined the term “hedonic hunger” in 2007. He says: “A lot of overeating, maybe all of the eating people do beyond their energy needs, is based on consuming some of our most palatable foods.” No kidding! Please don’t tell me it took years of scientific research to work that out. Who gets fat on cucumber?

Research shows that extremely sweet or fatty foods light up the brain’s reward circuit in the same way that cocaine, drugs, gambling and other ‘addictive’ behaviours do. The brain begins to react to fatty and sugary foods even before they enter our mouth: just seeing them excites the reward circuit. As soon as such it touches the tongue, taste buds send signals to the brain, which ramps up dopamine. The result is an intense feeling of pleasure.

Over time, the brain gets desensitised, so to get the same ‘high’ or pleasurable feeling, we need to eat more. It’s the same with any addiction. We need a bigger and bigger hit. The brain needs a lot more sugar and fat to reach the same level of pleasure that it once felt with smaller amounts of the foods.

This isn’t a sign of us being weak. It’s us being in thrall to an addictive circuit in our brain. When dopamine levels drop, we feel down. So no wonder we turn to fat and sugar. They are literally acting as an anti-depressant. Food is acting like a drug.

Perhaps you turned down a slice of cake, but now you find yourself at the plate, knife in hand, just making sure that the edge is even. You cut a sliver and shove it into your mouth. The cake tastes delicious. You return to the platter and ease off another morsel. Now the edge is a mess. You take the knife again and cut to smooth the ends. A short while later, the cake is considerably smaller…

It’s very easy to say that one mouthful won’t make a difference. The question is then, which mouthful makes us fat? Is it the first? Or the hundredth?

Maybe your friends are saying, come on, you’ve done really well! One dessert won’t kill you! They are right, it won’t, but it’s very easy for that one dessert to become many.

There are many times we can tell ourselves ‘This doesn’t count’. I didn’t order a dessert – I ate it from my husband’s plate, so that doesn’t count. Or I was just clearing dishes, and it was a shame to let the rest go to waste. So I scoffed it rather than put it in the garbage.

It’s much easier to let ourselves off the hook than stick to a diet because diets require us to make a huge effort. They ask for such a large change. Everything we know, everything we do is thrown out of the window. Your normal eating habits are utterly disrupted to make way for a new miracle fix that promises amazing results.

This is mainly because most of us believe that losing weight is so hard, so painful and so mysterious, that only the truly radical solutions will work.

But what if that wasn’t the case at all? What if one tiny change was all that was needed?

I love the introduction to the scientific paper called Eating with our Eyes: “One of the brain’s key roles is to facilitate foraging and feeding. It is presumably no coincidence, then, that the mouth is situated close to the brain in most animal species.”

The mouth is close to the brain, indeed! This same paper talks of ‘food porn’. We are currently obsessed with images of food. Instagram feeds are crammed with photographs of meals and snacks. Cookery channels dominate television with depictions of luscious ingredients whisked into appetising meals. Food has become more forbidden than sex. We are ogling pictures of it in the same way that men used to sneak glances at 1970’s centrefolds.

In America, digital media influences more than 70 percent of the food eaten by households. Research show that “external food cues, such as the sight of appetizing food can evoke a desire to eat, even in the absence of hunger.” Again – no kidding… these scientists seem to spend years researching things that you and I knew to be true from a relatively young age.

What’s really interesting is that physical things occur within us, just from seeing a picture. We salivate (we all know that). But more worryingly, we produce insulin. Our bodies shoot out the hormone required to deal with the sugar even when we haven’t eaten it. And of course, when our insulin goes up, we crave sugar even more to balance it out. Even our heart beats faster in anticipation of the food.

This is where we need to track back to hunger. Food manufacturers know that seductive images of delicious food will draw us in, hungry or not. And our brains will take the trigger and act on it, without even consulting our conscious selves.

If we can stay in touch with our natural appetite, and eat when we are hungry, it reduces the impact of these external stimuli, and allows us to remain in control of what we eat and when.

I used to think that one tiny change would never result in the loss of the fifteen kilos that I wanted to shed. To lose that kind of weight, a change had to be dramatic, drastic, and most of all, tortuous.

Medical research is showing that is not the case at all. They examined the world’s fattest man, and to reach his astronomical weight, all you have to do is eat 300 calories more than you need, every day, for about twenty years. He was so large that they had to take him to hospital on a forklift truck. So basically, all you need to do, to become enormously fat, is to eat one Mars Bar too many, every day. Gosh, I thought. That’s so easy to do! I could easily eat a small bar of chocolate more than I need every day. And some days, I could eat several.

Luckily, the reverse is also true.

If you reduce you calories a little bit every day, even if only by 50, you will lose weight. That’s just one biscuit. If you eat one biscuit less, every day, over the course of a year, you’ll lose weight. About five pounds or two kilograms, to be exact.